Many designs of geodesic dome structures have been devised but so far as I am aware all of them utilize wooden beams for forming the edges of the triangular wall sections that make up the main portion of the structure.
In geodesic dome structures it is common practice to fabricate each triangular wall section with an exterior panel which is fastened to the exterior surfaces of the three beams forming the edges of the wall section. Then when the wall sections are fastened together to form the complete structure an interior finish panel is fastened to the interior side of each wall section, being attached to the interior sides of the beams. In the completed form of the structure, therefore, each wall section includes parallel exterior and interior panels which are separated by the thickness of the beams.
Particularly in cold climates or in any time or location where energy conservation is of premium importance, it is also the practice to insert an insulating material between the panels of the wall section. The effectiveness of the insulating material depends upon its thickness, which is the same as the thickness of the beams.
I have concluded that it is uneconomical to make very thick beams of wood, because of the immense wastage of material. I have therefore concluded that it is advantageous to make the beams of metal providing the metal can be formed in such a way as to utilize the material effectively while at the same time maintaining necessary structural strength.
Even where heat insulation and hence the thickness of the beams is not of premium importance, I believe there is a potentially great advantage in constructing a geodesic dome with a metal frame, providing that the various members of the metal frame structure are shaped in such a way that the inherent structural capability of the metal is effectively utilized, and also provided that the metal members can be fastened together in a way which is structurally strong but does not require excessive labor either in the factory or at the construction site.
The object of the present invention is to provide a method of making a metal beam for a geodesic dome structure, which method can be simply and economically carried out, and which produces a beam that will be structurally effective when incorporated into the geodesic dome.